Scratch Designed/Built Sailplane - Page 4 - RC Groups
Thread Tools
Apr 16, 2012, 05:35 PM
Build something.
Nodd's Avatar
There'll be more pictures, rest assured. Plans, assuming she flies that is, are a distinct possibility.
Sign up now
to remove ads between posts
Apr 16, 2012, 05:41 PM
was geht , müssen unten kommen
Keenan smith's Avatar
this is an awsome Plane!
Apr 16, 2012, 05:42 PM
Build something.
Nodd's Avatar
Grumble Grumble Grumble

Well I was making good progress working on attaching the wing to the fuselage. In preparation for that I fiber-glassed the trailing edge of the wing's center section yesterday. I guess I rushed the mixing of the second batch of 15 minute epoxy as 24 hours later its still tacky. GROAN :-(

I did some reading up on the subject & other than waiting a week to see what happens there's a few tricks to help get the stuff to dry. Applying heat with a heat gun was recommended (just not too much heat). I did that & it helped some. Next I left the wing out in the sun for a few hours...

Again that's helped a little, still tacky though GRRRR. In other reading I hear acetone or vinegar can be used to remove uncured epoxy. I think I'll give it another day before stinking up my airplane with vinegar or whatnot. Fingers crossed it'll be dry tomorrow. In the mean time I'm constructing a PVC pipe plane rack for my over crowded workshop.
Last edited by Nodd; Apr 17, 2012 at 10:59 PM.
Apr 16, 2012, 07:44 PM
I'm All Thumbs
AirBornOne's Avatar
Never,ever have I heard of vineagar being used to remove uncured epoxy.
Acetone,maybe.Never tried it cause rubbing alcohol is what I've used to thin & cleanup uncured epoxy.99% if you can find it.
Sorry to hear of that sticky mess on your wonderful project Nodd.
I've had trouble with 30min and usually only use 5min or West Systems.
Apr 16, 2012, 08:16 PM
Build something.
Nodd's Avatar
Yeah the vinegar suggestion came from some sailboat forum. The guy said it was a good non-toxic alternative to using acetone for cleanup or dealing with uncured stickiness. Thanks for the rubbing alcohol suggestion. Hopefully the wing will be done curing by tomorrow. Fingers crossed.
Apr 16, 2012, 08:28 PM
Build something.
Nodd's Avatar
Although kinda off topic I thought this might be of interest. Here's how my PVC pipe plane rack turned out. I can't take credit for the idea, saw similar racks on a few YouTube videos. Sure is nice to have my park flyers up & out of the way...

Apr 16, 2012, 11:34 PM
Build something.
Nodd's Avatar
Even though I have a sticky wing to work with tonight I decided to push on & see if I can get the wing to sit pretty on the fuselage. The first challenge was to carve the airfoil bottom profile into the wing saddle area of the fuselage. I could have used my original airfoil graph but I wanted real world measurements to insure a good fit. To do this I took a photo of the wing's root area then created a template from the printed photo...

Next I sanded the wing saddle to my marks. The center of the wing has 14° of dihedral so I needed a way to carve out a V shape in the saddle. Turns out I already had the perfect tool sitting in my waste basket. Earlier I hacked off the center section trailing edge as I wanted to install something a little beefier in that area. I glued some sandpaper to the discarded part & presto, a custom sanding jig tailor made for the job...

The saddle area still needs some fine tuning but that'll need to wait until I can sand this gooey fiberglass. The initial test fit looks pretty good though...

Apr 17, 2012, 06:29 AM
Registered User
Sunfire's Avatar
oh, the fuse is really pretty, matey

its wonderful what a lectric sander can do
Apr 17, 2012, 04:30 PM
was geht , müssen unten kommen
Keenan smith's Avatar
Apr 17, 2012, 09:53 PM
Registered User
boingk's Avatar
Looking great mate, love that you've designed this one from scratch and followed through.

Keep it up!

- boingk
Apr 17, 2012, 10:40 PM
Build something.
Nodd's Avatar
Thanks guys. Yeah this is becoming quite the project, lovin' every minute of it.
Apr 17, 2012, 10:41 PM
Build something.
Nodd's Avatar
The evil epoxy-of-doom is dry. Woohoo!
Only took 48 hours for my 15 minute epoxy to cure. Nodd's new workshop rule...
  • 5 minute epoxy - mix for one full minute
  • 15 minute epoxy - mix for at least two minutes
I probably mixed it for all of 30 seconds as I was in a bit of a rush. BIG MISTAKE. Well back to the build...

Bolts or Bands
Some of you folks are probably going to give me all sorts of grief over this decision but it is, what it is. I've used both wing mounting systems, nylon bolts & good old rubber bands. Both have their pros & cons. Bolts make for a slicker install but on a high aspect wing can be somewhat unforgiving during a cartwheel landing. Rubber bands look dorky but are more forgiving during those inevitable D'OH moments. I chose to go with the latter...

At least I used spiffy carbon fiber instead of dowel...

In an effort to redeem my tarnished sense of style, I next went about carving probably the most complex shape imaginable...

I have no idea what this part is called, a fairing of some sort. Anyway it goes on top of the wing to help blend things in with the fuselage...

After much head scratching I figured out a neat way to carve the wing's shape into this fiddly little piece. I taped some sand paper to the wing & began rubbing. That's cheating I know...

A quick test fit (& no these wimpy little bands aren't for flying)...

That fit is close enough. Filled the gaps with a little putty & I'm done for the night...

Apr 18, 2012, 12:10 AM
Registered User
boingk's Avatar
That part is called a 'turtledeck' and aims streamlining significantly. Look at a waterdrop - most of the effective streamlining is in the rear. They're indispensible bits of gear for efficient aircraft, good work on the effort required to make one!

Cheers - boingk
Apr 18, 2012, 08:29 PM
Build something.
Nodd's Avatar
Turtledeck, that's right! I knew there was a name for it. Thanks for joggin' the noggin'.

V-Tail Time!
With the wing & fuselage pretty much complete its time to turn my attention towards the tail. I mocked up an initial v-tail structure in my CAD software...

I've not decided if I'll go with a symmetrical airfoil for the tail or just be lazy & build a flat cross section & do some sanding to smooth/taper things out. Either way it'll likely look something like this.

Its movie night at my home theater so no building tonight (watching the new Mission Impossible flic on my monster sized 108" screen). Will pick this up again tomorrow. On the plus side, I get to sleep on the v-tail design which usually results in a better/improved design come morning anyway.
Apr 19, 2012, 11:57 PM
Build something.
Nodd's Avatar
So I woke up today with this uber-sweet idea to make the v-tail even cooler. So I sat down at the 'puter & added fairings leading into the tail-feathers...

Yeah so much for sleeping on it. Will shelf that idea for another plane maybe. So anyway I went back to yesterday's v-tail design & added more detail to the structure. Then printed the design & started assembly...

Will have more to show soon.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Scratch-built 28" FFF Tiger Moth biplane (first scratch build) mclarkson Foamies (Scratchbuilt) 20 Apr 04, 2012 03:39 PM
Build Log Designing for scratch-built FPV wing... PiperCub49 Flying Wings 15 Mar 09, 2012 10:15 PM
Build Log Scratch built own design foamie... "Whiplash" glydr Australia 30 Jul 09, 2006 06:28 AM
Question Scratch built design? Perseus Large Scale Cars 2 Dec 11, 2005 06:02 PM
How do you design your scratch built jets? Florin777 Electric Ducted Fan Jet Talk 17 Mar 18, 2003 06:34 PM